1. Field of the Invention
The present invention relates to a device for controlling at least one barrier and/or at least one light signal at a grade crossing.
2. Description of the Related Art
In a conventional control of light signals at a fully barriered grade crossing, the light signals are activated so early before the expected arrival of a train, i.e. switched to red, that it is avoided with great probability, upon the subsequent closing of the full barriers, that vehicles are closed in on the grade crossing. The actuation of the light signals takes place, for example, using an established lead time before the closing of the barriers. The barriers, in turn, are closed using a specified clearance in time before the expected arrival of the train.
Published German patent application document DE 196 12 579 A1 describes a system for monitoring a danger zone, at full barrier grade crossings, having a rotating radar range finder which scans the danger zone horizontally. At the defined boundary of the danger zone, reference marking points are situated, in order to limit the scanning to the area within these marking points. Alternatively, sector elements of the danger zone may be stored according to length and angle, and the scanning of the danger zone using electronic means may be limited to the stored sector elements. The closing of the barriers is prevented if an object of a certain size, for instance, a vehicle or a person is located on the roadway surface in the danger zone of the grade crossing.